Electrical winding construction



May 27, 1958 B. M. GOLDSMITH 2,836,805

' ELECTRICALWINDING CONSTRUCTION Filed Dec. 4,1956

Wrmuu INVENTOR 5MM/PD /f/l, 60mm/m ATTO R N EY5 ELECTRIAL WlNDING CONSTRUCTION hf'. Goldsmith, Westeld, N. J., assignor to Essex Electronics, Berkeley Heights, N. J., a corporation of New VHersey Application December 4, 1956, Serial No. 626,175

Claims. (Cl. 336-136.)

My invention relates to an improved electrical coil and transformer construction, rendering the same particularly useful in the automatic assembly of such circuit components into circuit subassemblies, as into printed circuits.

it is an object of the invention to provide an improved construction of the character indicated.

it is another object to provide an improved electrical coil circuit element which can be fabricated at substantially reduced cost.

it is in general an object to meet the above objects with extremely rugged and simple device which can achieve or exceed the electrical performance of previous structures and which may be so rugged and permanent as to constitute a trouble-free component for the life of the circuit into which it is embodied.

Other objects and various further features of novelty and invention will be pointed out or will occur to those skilled in the art, from a reading of the following specilication in conjunction with the accompanying drawings. said drawings, which show, for illustrative purposes only, preferred forms of the invention:

Fig. l is an exploded View of essential components of a transformer construction embodying my invention, and with the body portion shown in longitudinal section;

Fig. 2 is a longitudinal sectional view of the fully assembled transformer of Fig. l;

Fig. 3 is a top end View of the assembly of Fig. 2, certain of the leads being shown in section, as viewed along the line 3 3 of Fig. 2.

Fig. 4 is a fragmentary longitudinal sectional view illustrating a modification of Fig. 2;

Fig. 5 is a fragmentary top view of the modification of Fig. 4; and

Figs. 6 and 7 are longitudinal sectional views of further embodiments.

Briefly stated, my invention contemplates application to the construction of coils, transformers, chokes, and the like, for use in electronic circuit assemblies as, for example, in the video amplitier of a television set. The invention features integral formation of the turns of the electrical coil with the mounting leads or prongs, and for this purpose, employs relatively heavy, stiff wire for the turns of the coil or coils. The assembly is made rugged and adaptable to receive an adjustably positioned magnetic core by casting the same in a plastic bonding agent, such as an epoxy resin. Various forms will be shown and described.

ln Figs. 1, 2 and 3 of the drawings, my invention is shown in application to a transformer construction employing an inner or primary winding and an outer or secondary winding 11, all contained and solidly embedded in a body 12 which, for convenience in handling, is cylindrical and which, for unambiguous angular orientation, may be formed with an elongated locating rib or key i3 at one angular location. Each of the windings luv-ll is developed from relatively stiff and heavy insulated Wire and is lshown as a single layer of fdr ctt.

e States Patent @fico 2,836,805 Patented May 27, 1958 turns, the ends of which are so formed and trimmed as to project axially beyond the axial contines of the coils; heavy plastic-coated copper magnet wire or Copper- Weld (copper-sheathed steel) wire provide adequate windings.

rThe wire from which windings 10-11 are formed is preferably so rugged that the projecting ends 14-15 of coil if: and the projecting ends 16-17 of coil 11 may serve as the mounting pins for the finished structure, so that no soldering or other connection to separate mounting pins is necessary to integrate the circuit component into its ultimate chassis. For convenience in mounting, the leads 14--15 and 16-17 are preferably nail-pointed, as illustrated at 18, and, if desired for unambiguous terminal identification, one of the leads for each winding may be caused to project axially further than the other lead for the same winding. Also, if desired (as for unambiguous mounting) and as illustrated in Fig. 3, the respective leads 14--15-16-17 may `be oriented within the transformer assembly at non-uniformly spaced intervals.

The body 12 for the transformer may comprise a cup-shaped shell, shown separately in Fig. l, and preferably formed of suitable plastic, such as molded high temperature nylon, fiberglass, polystyrene, or the like. The body 12 is shown to comprise an inner tubular member 19 and an outer tubular member 20, connected to each other at 21 at one axial end, so as to define therebetween an annular space 22 for reception of the coils or windings 10-11. Preferably, the inner winding or primary 10 is wound to a diameter such that it may be concentrically located upon the inner member 19, and the depth of the opening 22 is such as to receive and axially locate the Winding 10 on the bottom surface 23 for unambiguous automatic insertion, in such manner that the leads 14-15 project as desired beyond the open end of the body l2. The other or secondary winding 11 is preferably formed for concentric location on the primary winding lll and so that, when bottomed against the lead offset l5', its own leads 16-17 will project as desired beyond the open end of the body 12.

To complete the solid assembly once the windings 10-11 have been inserted, the windings are fully potted within the opening 22, as by employment of a quicksetting plastic potting compound 25, such as an epoxy resin.

In order that body 12 may accommodate a magneticcore element 26, l prefer that a bore 27 shall extend the full length of the body 12 and that one or more elongated ribs 28 be formed therein at angularly spaced locations. Thus, for the case of a threaded core element 26, a selftapping engagement may be had with the ridges 28. For the arrangement shown in Fig. 2, the core element 26 has been inserted from the bottom and to the extent necessary to determine the desired electrical performance. When thus inserted, the friction, by reason of self-tapped 'threaded engagement, is found adequate to hold the adjustment throughout the life of the component. It will be noted from the drawing that I have indicated a preference that the coil or coils shall be located substantially axially inwardly of the housing end from which the core member 26 is inserted, the extent of such inward location being of at least substantially the diameter of core member 26; this relationship assures that core member 26 may be mechanically well supported by the bore 27 for the greatest possible range of adjustment of electrical performance of a given component assembly.

ln the arrangement of Figs. 4 and 5, I show that my transformer construction lends itself readily to electrostatic shielding as by merely spraying a metalizing coat, suggested by heavy dashed lines 29, around the full cylindrical periphery of the body 12. Ground connections 3 may be established directly to the shield 29, but in the form shown, a ground or anchor pin 30 is embedded in the body 12, as at the key portion 13 thereof, and projects axially beyond the mounting end of the assembly. If desired, the pin 30 may be embedded relatively close to the outer limit of key 13, as best shown in Fig. 5, so that by merely scraping away a local portion of the plastic of body 12 alongside pin 30, and prior to spraying the coat 29, it is possible to spray the coat 29 in good permanent electrical contact with the ground pin 3f), thus obviating any need to establish a further electrical connection between these parts. It will be noted that when a mounting pin 30, or for that matter, when a key 13 is employed, there is provided an unambiguous means for orienting the complete transformer assembly, so that (at least for mounting' purposes) there is no particular need that the leads 14--15-16--17 shall be of different lengths beyondy the end of the transformer body, or that they be at differently spaced angular locations.

In the arrangements of Figs.. 6 and 7, I show applications of my invention to a less expensive constructionV involving many of the same principles. The arrangement of Fig. 6 differs essentiallyrfrom that of Fig. 7 in that Fig. 6 shows a transformer having windings 35-36, whereas Fig. 7 shows but a single coil 37, which may be a choke coil. In each case, the winding or windings are supported on an inner tubular member 38 which may be of high-temperature nylon, fiberglass or polystyrene, or the like, and which is preferably formed with elongated inner ribs 39, as described at 28 for the case of Fig. 2. n

Plastic bonding is achieved by merely' dripping a quicksetting plastic, such as an epoxy resin 40, over the winding or windings and overlapping the same onto the tubular core 38. If desired, a locating lug or key 41 may be formed with the tubular core or support 38 and a magnetic-core element 42 inserted, as discussed at 26 in con` nection with Fig.. 2. The leads for the various windings of Figs. 6 and 7 again are preferably formed integral with the turns of their respective coils and project axially in the same direction beyond the body of the assembly, the ends of the leads being nail-pointed as at 43, to permit non-fouling insertion in a suitable socket, not shown.

It will be appreciated that I have described an improved coil and transformer construction featuring extreme ruggedness and reduced cost of manufacture. My constructions are adaptable to completely automatic manufacture and, once having been manufactured, they are adaptable to fully automatic assembly into an ultimate chassis, as, for example, into a printed circuit, the key 13 or 41 (or the unambiguously located lead ends or prongs) being such as to facilitate automatic handling for automatic assembly.` My transformers are found to exhibit a clearly predictable frequency-drift Vcoefficient (as a function of temperature) which lends itself to the controlled determination of shift coefficient, as by employing at 25 or 40 a bonding or potting agent so constituted as to develop in the completed assembly a particular desired positive, negative or neutral drift characteristic.

While I have' described the invention in detail for the preferred forms illustrated, it will be understood that modifications may be made within the scope of the invention as defined in the claims which follow.

I claim:

l. In combination, a plastic tubular coil-supporting body member having inner and outer surfaces, and an electrical winding comprising a single layer of turns of relatively heavy and stiff wire deriving concentric support directly from the outer surface of said body member, one end of: saidV winding being straight and integrally formed; to project axially beyond the corresponding axial endV of said body member, the other end of said winding being" straight and integrally formed to run adjacent the radially outer side of said winding and to project axiallyV beyond the said axial end of said body member at a l0- cation angularly spaced from said first projecting end, the weight and stiffness of said wire being such that said projecting wire ends provide the substantial mounting support for said combination, and means permanently bonding said winding to said body member and said other straight end of said winding to said radially outer side of said winding.

2. In combination, a plastic tubular transformer body member having inner and outer surfaces, a first winding comprising a single layer of turns of relatively heavy and stiff wire deriving concentric support directly from the outer surface of said body member, a second Winding comprising a single layer of turns of relatively heavy and stiff wire deriving concentric support directly from the turns of said first winding, first corresponding ends of the wires for said first and second windings being straight and integrally formed to project axially beyond one axial end of said body member at angularly spaced locations, the other corresponding ends of the wires for said first and second windings being straight and integrally formed to run adjacent the radially outer side of said second winding and to project am'ally beyond said axial end of said body member at angularly spaced locations which are spaced from said first-mentioned angularly spaced locations, the weight and stiffness of said wires being such that said combination may be fully oriented and supported directly and solely by the projecting ends thereof, and means bonding said. windings to each other and to said one wall ofv said body memberrand bonding said straight other corresponding ends to said radially outer side of said second winding.

3. in an electrical-coil assembly,l a coil of relatively stiff wire with the ends of said coil projecting integrally and axially to serve as direct plug-type lead-in connections, a tubular plastic core engaging the radially inner side of said coil, whereby said coil may be initially located on said core, one of said wire ends being straight from one end of said coil and projecting axially beyond the corresponding axial end of said plastic core,the other of said wire ends being formed to run adjacent the radially outer side of said coil and tc` project straight beyond said axial end of said core in angularly spaced relation with said one wire end, whereby said projecting wire ends define lead-in connections, and a plastic bonding'material bonding said other wire end to said coil and said coil to said plastic core, the size and stiffness of said wire being sufficient in relation to the weight of said assembly for said lead-in connections to provide the substantial mounting support for said coil assembly.

4. In combination, a plastic body member comprising concentric inner and outer tubular portions connected at one axial end and defining therebetween an annular space open at the other axial end, a first winding of relatively stiff w'rre supported within said space and substantially on the outer surface of the inner tubular portion of said body, a second winding of relatively stiff wire axially overlapping andV supported by said first winding, the separate ends of both windings projecting to define integral plug-type leads at different angular locations axially beyond the open end of said body, the axially inner wire ends of said respective coils being integrally formed to run adjacent the radially outer side of said second winding, and plastic bonding material bonding adjacent parts of said inner wire ends to said second winding and bonding the turns of said windings to each other and to said inner tubular portion, the stiffness of said wire being such in relation to the weight of said cornbination that said integral plug-type leads Vprovide the substantial mounting support for said combination.

5. In combination, a generally cup-shaped container including an upstanding inner tubular member of electrically insulating material defining an annular space between inner and outer walls, a coil of heavy insulated wire in radially located relation with the inner one of said walls, and a potting of plastic material solidly filling that part of the said annular space in which said coil is located, the ends of said wire projecting freely and axially beyond the confines of said potting at the same axial end of said container, the wire end at the axially inner end of said coil being formed radially outwardly oliset and running straight alongside the outer side of said coil and within said outer wall, and the weight and stiliness of said wire being such in relation to the weight of said cornbination that said projecting wire ends may provide the substantial support of said combination.

6. In combination, a generally cup shaped container including an opstanding inner tubular member of electrically insulatingy material defining an annular space between inner and outer walls, a rst coil of heavy insulated wire having turns in radially located relation with the inner one of said Walls, a second coil of heavy insulated wire surrounding and in radially located relation with the turns of said first coil, and a potting of plastic material solidly filling that part of said annular space in which said coils are located, the ends of the wires of said coils projecting freely and axially beyond the contines of said potting and beyond the same axial end of said container, the wire ends at the axially inner ends of said coils being formed radially outwardly offset at angularly spaced locations and straight alongside the outer side of said second coil and within said outer wall, and the stiffness of said wires being such in relation to the weight of said combination that said projecting wire ends provide the substantial support of said combination.

7. ln combination, a generally cup-shaped container including an upstanding inner tubular member of electrically insulating material defining an annular space between inner and outer walls, a coil of heavy insulated wire in radially located relation with the inner one of said walls, and a potting of plastic material solidly filling that part of the said annular space in which said coil is located, the ends of said wire projecting freely and axially beyond the confines of said potting at one axial end of said container, the wire end at the axially inner end of said coil being formed radially outwardly offset and straight alongside the outer side of said coil and within said outer wall, the weight and stiffness of said wire being such in relation to the weight of said combination that said projecting wire ends may provide the substantial support of said combination, and a threaded ferromagnetic core member adjustably positionable in the bore of said tubular member, said coil being axially spaced from one end of said tubular member by an amount at least substantially equivalent to the bore diameter of said tubular member.

8. In combination, a generally cup-shaped container including an upstanding inner tubular member of electrically insulating material defining an annular space between inner and outer walls, a rst coil of heavy insulated wire in radially located relation with the inner one of said walls, a second coil of heavy insulated wire surrounding and in radially located relation with the turns of said rst coil, and a potting of plastic material solidly filling that part of said annular space in which said coils are located, the ends of the wires of said coils projecting freely and axially beyond the contines of said potting at one axial end of said container, the wire ends 'at the axially inner ends of said coils being formed r-adially outwardly offset at angularly spaced locations and straight alongside the outer side of 'said second coil and within said outer wall, and the stiffness of said wires being such in relation to the weight of said com bination that said projectin;` wire ends provide the substantial support of said combination, and a threaded ferromagnetic core member adjustably positionable in the bore of said tubular member, that coil which is axially nearest one end of said tubular member being spaced from said one end by an amount at least substantially equivalent to the bore diameter of said tubular member.

9. In combination, a generally cup-shaped container open at one end and including an upstanding inner tubular member of electrically insulating material defining an annular space between inner and outer walls, and an electrical winding having a single layer of turns of relatively heavy and stift' wire deriving concentric support directly from the outer surface of said inner wall, one end of said winding being straight and integrally formed to project axially beyond the open end of said container, the other end ot said winding being straight and integrally formed to run adjacent the radially outer side of said winding and to project axially beyond said open end of said container at a location angularly spaced from said iirst projecting end, the weight and stiffness of said wire being such that said projecting wire ends provide the substantial mounting support for said combination, and plastic means substantially closing the open end of said container and holding the straight projecting ends of said wire in angularly-spaced relation.

l0. ln combination, a generally cup-shaped container open at one end and including an upstanding inner tubular member of electrically insulating material defining an annular space between inner and outer Walls, a first electrical winding having a single layer of turns of relatively heavy and stiff insulated wire deriving concentric support directly from the outer surface of said inner wall, one end of said first winding being straight and integrally formed to project axially beyond the open end of said container, a second electrical winding having a single layer of turns of relatively heavy and stiff insulated wire deriving concentric support directly from the turns of said lirst winding, the axially inner ends of both windings being straight and radially oiset and running alongside the outer limit of said second winding and projecting axially beyond the open end of said container, the other end of said second winding being straight and integrally formed to project axially beyond the open end of said container, and plastic means substantially closing the open end of said container and holding the straight projecting ends of both said wires in angularlyspaced relation.

References Cited in the tile of this patent UNITED STATES PATENTS 1,489,370 Steinberger Apr. 8, 1924 1,533,749 Meirowsky Apr. 14, 1925 1,661,953 McIntosh Mar. 6, 1928 1,763,115 Wermine lune 10, 1930 2,404,404 Roberds July 23, 1946 2,553,339 Silvey May 15, 1951 2,695,856 Firth Nov. 30, 1954 2,715,094 Szekely Aug. 9, 1955 2,781,438 Grith Feb. 12, 1957 FOREIGN PATENTS 647,072 France Nov. 20, 1928 1,115,231 France Apr. 20, 1956 

